ELCOM Euro-500T Handy User manual

Euro-500T Handy
Service manual
© Elcom Ltd.
Version 1.0
Euro-500 Handy

Neither this manual, or any part of it, may be copied or distributed without
the consent of the Elcom company.
All rights of Elcom Ltd. are reserved.

© Elcom Ltd.
Service manual
3
Euro-500T Handy
Table of contents
1 INTRODUCTION ............................................................................................................................ 5
1.1 Euro-500T Handy cash register technical parameters ............................................................ 5
1.2 System configuration ................................................................................................................. 5
1.3 Cash register block diagram...................................................................................................... 5
2 CIRCUIT SCHEMES AND FUNCTIONS ........................................................................................ 6
2.1 Connection circuits .................................................................................................................... 6
2.1.1 External power supply ..................................................................................................... ............. 6
2.1.2 Primary connection circuit ............................................................................................................ 6
2.1.3 Voltage stabilizer .......................................................................................................................... 7
2.1.4 Printer connection circuit .............................................................................................................. 8
2.1.5 Secondary connection circuit ....................................................................................................... 8
2.1.6 Circuit for connecting the fiscal memory ....................................................................................... 9
2.1.7 Power supplies characterisation ................................................................................................... 9
2.2 Micro-controller and its support circuits ................................................................................ 10
2.2.1 E-500N micro-controller ............................................................................................................. 10
2.2.2 Memory circuits .......................................................................................................................... 12
2.2.3 System start and outage ................................................................................................... ......... 13
2.2.4 Current time circuit ..................................................................................................................... 13
2.3 Input-Output circuits ................................................................................................................. 14
2.3.1 Print control circuits .................................................................................................................... 14
2.3.2 Keyboard .................................................................................................................................... 16
2.3.3 Displays ..................................................................................................................................... 17
2.3.4 Communication circuits .............................................................................................................. 20
2.3.5 Interconnection of FM circuits ..................................................................................................... 21
2.3.6 Other circuits ............................................................................................................................. 22
3 THE MLT-288 THERMAL PRINTER ............................................................................................ 24
3.1 Basic layout ............................................................................................................................... 24
3.2 Thermal head ............................................................................................................................ 24
3.2.1 Thermal head composition ......................................................................................................... 24
3.2.2 Thermal head data processing ................................................................................................... 25
3.2.3 Print data and their position ........................................................................................................ 25
3.2.4 Thermistor layout ....................................................................................................................... 25
3.2.5 Time chart .................................................................................................................................. 25
3.3 Paper shifting ............................................................................................................................ 26
3.3.1 Stepping motor layout ................................................................................................................. 26
3.3.2 Excitation sequence ................................................................................................................... 26
3.3.3 Control circuit ............................................................................................................................. 26
3.4 Sensor of head position ........................................................................................................... 27
3.5 Sensors of paper ribbon end ................................................................................................... 27
3.6 Overall time chart ...................................................................................................................... 27
3.7 Printer connectors .................................................................................................................... 28
3.7.1 Thermal head connector ............................................................................................................ 28
3.7.2 Motor and sensors terminal ........................................................................................................ 29
3.8 How to clean thermal head ...................................................................................................... 29
4 MODULE (RE)INSTALLATION .................................................................................................... 30
4.1 Dismantling the cash register .................................................................................................. 30
4.2 Accumulator replacement ........................................................................................................ 32
4.3 Printer replacement .................................................................................................................. 33
4.4 Motor replacement .................................................................................................................... 34
4.5 Electronics mainboard replacement ....................................................................................... 35
4.6 EPROM replacement ................................................................................................................ 36
4.7 Replacement of damaged SRAM or replacement of SRAM with higher capacity .............. 36

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Service manual
Euro-500T Handy
4.8 NiCd battery replacement ........................................................................................................ 37
4.9 Keys and keyboard replacement ............................................................................................ 37
4.10 Replacement of displays .......................................................................................................... 39
4.10.1 Replacement of Euro-500T Handy (segment/segment) displays ................................................ 39
4.10.2 Replacement of Euro-500T Handy (alpha/segment) displays ..................................................... 40
4.11 Cash register connectors ........................................................................................................ 41
4.11.1 Connectors on mainboard of electronics ....................................................................................41
4.11.2 Connectors for connecting external appliances .......................................................................... 41
4.12 Back-light installation of segmented LCD display ................................................................ 42
4.13 Connecting of external drawer ................................................................................................ 43
4.14 Connecting of external keyboard ............................................................................................ 44
4.15 Interconnecting of Euro-500T Handy and PC through RS-232 interface ............................ 45
4.16 Connecting of scanner and scales through RS-232 interface ............................................. 45
5 CASH REGISTER TESTING ........................................................................................................ 46
5.1 Test of displays ......................................................................................................................... 46
5.2 Printer test ................................................................................................................................. 47
5.2.1 Testing of printing ....................................................................................................................... 47
5.2.2 Testing of scanning the thermal printer head position .................................................................. 47
5.2.3 Testing of paper ribbons sensors .......................................................................................... ...... 48
5.3 Keyboard tests .......................................................................................................................... 48
5.3.1 Keyboard test 1 .......................................................................................................................... 48
5.3.2 Keyboard test 2 .......................................................................................................................... 49
5.4 Communication interface tests ............................................................................................... 50
5.4.1 Test of RS-232C serial interface for the PC ................................................................................50
5.4.2 Test of RS-232C serial interface for the scanner and electronic scales ...................................... 50
5.4.3 The test of serial interface for the external PC keyboard ............................................................. 51
5.5 Test of cash register drawer .................................................................................................... 52
5.6 Fiscal memory tests .................................................................................................................. 52
5.6.1 Tests of data reading from the fiscal memory ............................................................................. 52
5.6.2 Test of data recording to the fiscal memory ................................................................................53
5.6.3 The operating voltage control for the fiscal memory .................................................................... 53
5.6.4 The test of the control signals I for the fiscal memory ................................................................. 54
5.6.5 The test of the control signals II for the fiscal memory................................................................. 54
5.7 Test of the control sum of EPROM memory ........................................................................... 55
5.8 Battery tests .............................................................................................................................. 55
5.8.1 The test of battery condition ........................................................................................................ 55
5.8.2 The test of VCC1 supply ............................................................................................................. 55
6 FAILURE REMOVAL .................................................................................................................... 56
6.1 Failures in supply section ........................................................................................................ 56
6.2 Failures of micro-processing system ..................................................................................... 57
6.3 Failures of print ......................................................................................................................... 58
6.4 Failures of visual display ......................................................................................................... 60
6.5 Failures of keyboard ................................................................................................................. 60
6.6 Failures of communication ...................................................................................................... 61
6.7 Failures of current date and time............................................................................................. 61
6.8 Other failures ............................................................................................................................. 61
7 THE LISTS OF PCB COMPONENTS .......................................................................................... 62
7.1 Classification of cash register components .......................................................................... 62
7.2 List of electronics mainboard components ........................................................................... 62
7.3 List of keyboard components..................................................................................................69
7.4 List of display segmented module components ................................................................... 69
7.5 List of components on board of connectors ......................................................................... 70
7.6 List of components on interconnection board ...................................................................... 70
7.6.1 List of components on interconnection board of Euro-500T Handy (segment/segment) .............. 70
7.6.2 List of components on interconnection board of Euro-500T Handy (alpha/segment) ................... 71

© Elcom Ltd.
Service manual
5
Euro-500T Handy
1 Introduction
1.1 Euro-500T Handy cash register technical parameters
The Euro-500T Handy is a portable electronic cash register with the following technical parameters:
primary connection external adapter 230 V, 50-60 Hz/12 V, 1200 mA
internal connection NiMh accumulator 7,2 V, 1500 mAh
or lead accumulator 6 V, 1200 mAh
maximum power consumption 10 W
micro-processing system 16-bit micro-controller, 256 kB EPROM, 128 or 512 kB
memory backup NiCd accumulator 3,6 V, 60 mAh
printer electrothermal, CITIZEN MLT-288
customer and cashier display 2x segmented LCD
alphanumeric LCD 2x20 characters for cashier, segmented LCD for customer
keyboard 30 regular keys and 1 double key
1.2 System configuration
The Euro-500T Handy is designed as a portable electronic cash register. The main parameters of a portable cash register are: low
weight, small size and a guarantee of longevity without an external connection.
The E-500N 16-bit micro-controller with 11 I/O ports and 2 portable channels is the center of the cash register. The cash register
program is stored in the 256 kB EPROM. Depending on the program version in EPROM memory, the micro-controller works with
RAM memory with a capacity of either 128 or 512 kB.
System contains:
connecting circuits
micro-processing system
current time circuit
reset controller (reset control circuit)
circuit controlling power supply value
keyboard interface
display interface
printer interface
RS-232 serial interfaces for PC, scanner and electronic scales
interface for connecting external PC keyboard
circuits for power reduction
circuit for drawer opening
circuit for scanning paper ribbon end
back-light of cashier display (optional for segment cashier display)
back-light of customer display (optional)
fiscal memory with support circuits (optional)
external accumulator - battery box (optional)
1.3 Cash register block diagram
EPROM
256 kB
SRAM
128 (512) kB
8-bit data bus
19-bit address busA 0 - A 1 8
D 0 - D 7
Current
time circuit
RS 232
interface for PC
RS 232 inter-
face for scanner
and scales
External
PC keyboard
Power voltage
checking
Paper ribbon
present
checking
Display
Fiscal
memory
Printer
Keyboard
Control bleeding
current circuit
MICROCONTROLLER
E-500N

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Service manual
Euro-500T Handy
2 Circuit schemes and functions
2.1 Connection circuits
2.1.1 External power supply
230 V, 50-60 Hz/12 V 1200 mA network adapter functions as an external power supply.
It has two main functions:
the cash register is connected directly to a 230 V/50 Hz ground socket
recharging of the internal accumulator is provided through the primary connection circuit
2.1.2 Primary connection circuit
If the external power supply is used, the primary connection circuit provides for recharging of the internal accumulator and for
connecting of the cash register. The basic component of this circuit is a universal MC34167 (5 A) unidirectional inverter with a
built-in high-voltage and thermal protection. The high-voltage protection operates at 6,5 A. Being a switching supply with a
voltage oscillation frequency of 72 kHz, it prevents network interference. Its 80% efficiency provides for the effective voltage
conversion and low loss of heat (minimum requirements for circuit cooling).
Figure 2.2 Primary connection circuit
Figure 2.1 External power supply
Note: After connecting the external power supply to the cash register, recharging of the internal accumulator is possible even
if the cash register is switched off.
INPUT
AC 230V/50Hz
T1
TRANSFORMER
D1 D2
D3 D4 C1
+OUTPUT
DC 12V
RESETABLE THERMAL FUSE
C3
330u/25V
C6
2200u/25V
R1
6k8
R2
10k
R4
6k8
R3
68k
D2
1N5822
2
1
5
4
3
U13
MC33167+cooler
C1
1u/35V
C2
1u/35V
3
4
2
1
EMI
FILTER
EF1
2x3,3mH/1,5A
VIN
ADP+
ADP-
VSS
C5
100n
C4
100n
L1
120u (2A)
C1x
1u/35V(A)
C2x
1u/35V(A)
R7
2k2
JPB2
BATSEL2
D1
1N5822
D3
1N5822
R8
470R
8,85V± 0,05V (NiMh Battery)
6,9V±0,1V (Sealed Battery)
BATSEL2 interconnected for NiMh battery
BATSEL2 not interconnected for sealed battery

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Service manual
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Euro-500T Handy
+4,9 ±0,05V (only if SAVEPWR is logic 1)
C7
330u/25V
VCC1VCC
SAVEPWR
T15
RFP15P05 (SFP9Z34)
R29
100k
T14
BC817
R35
100k
T16
BC817
R113
100k
LVOFF/NMI
+5 ±0,05V
+ 4,8 ± 0,05V
BATSEL3 is interconnected for sealed battery
BATSEL3 is not interconnected for NiMh battery
1
2
BATT
AVA 5400-2P-S
R5
510R
R9
1k0/F
C9
2200u/25V
BT1
3V6, 60mAh
VCC VRAM
VBAT
D4
1N5819
21
4
3
U14
KA278R05
F1
3.15A+holder
JP1
Batt 3p
VCC
2
GND
3
RST
1
U12
V6340/F
R6
6k8
LVOFF/NMI
LVOFF/NMI
VBAT1
C8
1u/35V
1
2
PWRSW
AVA 5400-2P-S
D3
1N5822
D20
LL4148
JBP3
BATSEL3
C13
100n
C70
100n
R30
0R
R112
47k
VBATf
NMI
RST
1
IN
2GND
3N.C. 4
N.C. 5
U12A
NCP301LSN45T1
LVOFF/NMI
COMPIN Values of components for different comparators:
V6340/F NCP301LSN45T1
R5
R6
R112
47K 0R
6k8 22k/F
2k/F510R
R50 47k 10k
2.1.3 Voltage stabilizer
To reduce the amount of power, logical circuits of the cash register are divided into two groups:
1. the group connected by VCC voltage, which can be switched on only by a PWSWR switch
2. the group connected by VCC1 voltage, which can be switched by the micro-processor only when printing,
communicating and recording into the fiscal memory
The U14 voltage stabilizer functions as a means to switch on and stabilize a VCC connecting voltage for the first group of the cash
register logical circuits. The circuit was designed to be switched on by a PWRSW on/off switch connected through AVA 5400-2P-S 2-
pin connector. T14, T15, and T16 transistors produce VCC1 voltage for the second group of logical circuits. They are operated by a
micro-processor SAVEPWR signal. An integrated U12 circuit controls the values of the battery voltage. If the voltage gets too low it
automatically generates the signal for switching off the supply.
To keep current time and data stored in RAM memory, the cash register is supplied with a reserve BT1 battery. When the cash register
is switched on the battery is being recharged through R9 resistor and when the cash register is switched off it serves as a supply of the
reserve voltage.
Figure 2.3 Voltage stabilizer
Measured values:
VBAT1: 6,0 V +0,3 V -1 V; when using the internal accumulator without the connected external adapter
(the supply is automatically switched off at a voltage of 5 V),
6,9 V ±0,2 V; when using the lead accumulator with the connected external adapter.
VBAT1: 7,6 V +0,9 V, -1 V; when using the internal NiMh accumulator without the connected external adapter
(the supply is automatically switched off at a voltage of 6,6 V),
8,4 V +0,2 V, -0,6 V; when using NiMh accumulator with the connected external adapter.
VRAM: 4,8 V ±0,05 V; when the cash register is switched on (VCC = 5 V),
3,6 V +0,5 V -0,1 V; when the cash register is switched off (VCC = 0 V).
Note: The removal of the JP1 jumper when the cash register is switched off will cause the deletion of all data in RAM memory and in
the current time circuit.
Internal accumulator scheme
Accumulator BATT
+ (red) 2
-(black) 1

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© Elcom Ltd.
Service manual
Euro-500T Handy
2.1.4 Printer connection circuit
The printer connection circuit stabilizes the VH connecting voltage for the printer power circuits. This voltage is at the same time
the input voltage for the secondary connection circuit.
To guarantee the security, the supply is controlled by LVOFF/NMI signal too (switching off at the drop of a battery voltage). The
micro-processor activates the VH voltage circuit with a SAVEPWR signal only when the cash register is not in the save or
standby mode. A cut-off of D15 diode by JPB3 jumper occurs only when using the lead battery.
Measured values:
It is possible to measure VH voltage only when printing or testing (test 910, see the chapter 5).
VH - in a version with the lead battery; the VH values are very close to those of VBAT1 given in the chapter 2.1.3,
- in a version with NiMh battery; comparing the VBAT1 and VH values, the latter are lower approximately
by 0,8 - 1 V (loss in D15 diode).
Figure 2.4 Printer connection circuit
2.1.5 Secondary connection circuit
The secondary connection circuit produces the voltage necessary for work with the fiscal memory.
The secondary connection circuit functions as a switching supply with 87% efficiency and a switching frequency of 33 kHz. VH
voltage becomes an input voltage of the secondary connection circuit. The output voltage of this circuit is 13,5 V. The inverter
contains a high-voltage and thermal protection. The high-voltage protection activates when the value of power supply is higher
than 1,35 A.
Figure. 2.5 Secondary connection circuit
BATSEL1 is interconnected for sealed battery
BATSEL1 is not interconnected for NiMh battery
R20
100k
R21
1M
LVOFF/NMI
VH
R22
100k
RST
T6
RFP15P05 (SFP9Z34)
T7
BC817
T8
BC817
T9
BC817
R28
100k
SAVEPWR
D15
1N5408
JPB3
BATSEL1
VBATf
8
7
6
5
1
2
3
4
U15
MC34063
R13
220R
R14
0R22
R12
22k/F
R10
2k0/F
C12
330u/25V
D5
1N5819
VH
13,5 V
R11
220R
C11
100n
C10
1n
L2
120u (625mA)

© Elcom Ltd.
Service manual
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Euro-500T Handy
2.1.6 Circuit for connecting the fiscal memory
When using the fiscal memory, a production of the voltages for programming, verification, and reading data from this memory is
inevitable. The voltages are produced with a help of the following circuit.
Measured values:
VPP-GEN = log. 0 VFP: 4,8 V ±0,1 V VFD: 4,8 V ±0,1 V (independent on SAWEPWR)
VPP-GEN = log. 1 VFP: 13 V ±0,5 V VFD: 6,4 V ±0,15 V (SAVEPWR = log. 1)
Figure 2.6 Circuit for connecting FM
2.1.7 Power supplies characterisation
VH connecting of the printer power circuits and of the secondary connection circuits
values: 6V +0,3V -1 Vfor the lead battery without the external adapter,
6,5 ±0,3V for the lead battery with the external adapter,
7,6 +0,8V -1V for NiMh battery without the external adapter,
8,4 +0,2V -1V for NiMh battery with the external adapter.
VCC connecting of a logical part
value: 5 V ±0,1 V.
VRAM power supply of the micro-processor, of RAM memory, and of the current time
values: 4,1V +0,1V -0,5V when the cash register is switched on,
3,6V + 0,5V -0,1V when the cash register is switched off.
R18
220R/F
VFD
VFP Vout
2
Vout
7
NC
5
Vout
6
Vout
3
Vin
1
Adj
4
NC
8
U16
LM317L
R15
100k
R17
100k
R16
100k
RST
VPP-GEN
13,5 V
D6
1N5819
VCC
R19
1k0/F
D8
1N5819
VCC
C14
100n
D7
LL4148
T5
BC817
T4
BC817
T3
BSS84
C49
1u/35V
VFP
C15
1u/35V
C15x
1u/35V(A)
C49x
1u/35V(A)
D18
LL4148
PV PV

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© Elcom Ltd.
Service manual
Euro-500T Handy
2.2 Micro-controller and its support circuits
2.2.1 E-500N micro-controller
The E-500N 16-bit micro-controller used in the Euro-500T Handy cash register secures complete control over the cash register activity.
Its characteristics are:
chip has 2 kB RAM
11 input-output ports
addressing of program memory max. 16 MB
addressing of data memory max. 16 MB
five 16-bit readers/timers
seven external interruptions
two complete USART duplexes (serial channels)
10-bit A/D inverter, eight channels
8-bit D/A inverter, two channels
watchdog timer
timing frequency up to 18 MHz
oscillator and chip conjugation circuit
QFP 100 case
See Figure 2.7 for the circuit pin layout and Table 2.1 for its description.
Figure 2.7 E-500N micro-controller
VRAMx
FM-AL/CN0
FM-AH/CN1
A16/CN2
FM-DIR/SCL
SDA
FM-SEL
FM-PGM
VPP-GEN
NC
GND
TXD0
TXD1
RXD0
RXD1
EKB-DAT
EKB-CLK
FD0
FD1
FD2/RW2
FD3/RW3
FD4/RW4
FD5/JP4
FD6/JP5
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
23
24
25
22
FD
7
/
D1
D2
D3
D4
D5
D6
D7
V
R
AM
x
A0
A1
A2
A3
A4
A5
A6
A7
GN
D
A8
A9
A10
A11
A12
A13
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
A14
A15
A16
A17
A18
NC
GND
LCD-SEL
NC
STBY
RST
GND
EXTAL
XTAL
VRAMx
NC
RD
NC
MD0
MD1
MD2
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
E - 500N
N
C
C
S
4
E
N
S
A
V
E
P
W
R
B
A
U
N
M
T
P
C
LK
PR-SEL
GND
CS0x
CS1
CS2
RDKEYB
GND
BUZZER
DRAWER
HSx
PS2x
PS1x
P-LOW
TSx
VREF
AVCC
POWER
JP6
D0
LCD-CLK
LCD-D/DPR
NMI
HWR